The present invention relates to an information displaying method and a plant-operation monitoring apparatus for monitoring plant operations. In particular, the present invention relates to a method for displaying information on an unsteady event such as an alarm.
Traditionally, information on plant operations comprising drawings and texts is displayed on a picture. When an unsteady event such as an alarm occurs at an unexpectable time, in order to indicate that the event is associated with a figure illustrating a normal condition on the picture, the figure is put in a blinking state or shown in a different color.
A string of characters describing details of the unsteady event is also displayed at a location in close proximity to the figure related to the unsteady event or at a specific location on the displayed picture along with the name of an object relevant to the occurring unsteady event.
In the display of such a conventional plant monitoring picture, the number of displayed items is limited by the display area and, in addition, a relation with a figure showing an object normally being monitored is not clear.
Moreover, when the figure of a monitored object is put in a blinking state to display the occurrence of an unsteady event, there is a shortcoming that it is difficult to recognize the blinking figure because, the more complex the picture drawn in advance, the smaller the individual picture elements. Furthermore, even though a notification of the occurrence of an unsteady event based on a blinking figure allows a relation between the occurrence of the unsteady event with the figure drawn in advance to be confirmed, it is difficult to understand information more detailed than the relation by merely seeing the displayed picture at a glance.
These problems serve as a big hindrance to plant operation monitoring in which it is necessary to immediately obtain information on circumstances of the plant in the abnormal occurrence of an alarm or the like.
As described above, an explanation by using a string of characters may be added to the picture for compensating the display for such an inadequate amount of information by adopting a technique of displaying such an explanatory string of characters at a location in a close proximity to a pre-drawn figure related to the occurring unsteady event. In this case, however, it becomes difficult to distinguish the explanatory string of characters from other character strings which are displayed continuously. With the technique for displaying an explanatory string of characters at a specific location on the picture, on the other hand, the name of an object must be displayed as another string of characters to indicate the relation with a pre-drawn figure relevant to the occurring unsteady event, making it also difficult to understand the relation by the sense of sight at a glance. These problems also serve as a hindrance to an attempt made to understand the displayed information quickly.
There may be a case in which the operation of a plant needs to be continued even if an unsteady event occurs. In this case, it is necessary to continuously display the alarm of the unsteady event on the picture, even after the user confirms the alarm notification, till the abnormal state is removed. In order to meet such a requirement, it is necessary in some cases to display a number of unsteady event notifications simultaneously on the picture. Once a blinking state has been terminated, however, figures already drawn on the picture can be distinguished from each other only by colors. In addition, if the technique for displaying a string of characters on a specific area of the picture is adopted, there is a limit on the number of character strings that can be displayed. With the technique for displaying a notification at a place in close proximity to an already drawn figure, on the other hand, there is raised a problem that, the greater the number of displayed notifications, the more difficult the notifications to distinguish from the continuously displayed character strings. As a result, the notifications of unsteady events serve as a hindrance to the display of information other than the unsteady events.
An example of a technique for displaying information on a unsteady event occurring at a plant is disclosed in Japanese Patent Laid-open No. Hei 4-269626.